Lead acid batteries are well known. All lead acid batteries include at least one positive electrode, at least one negative electrode, and an electrolytic solution of sulfuric acid (H2SO4) and distilled water. The actual chemical reaction, which allows the battery to store and release electrical energy, occurs in a paste that coats the electrodes. The positive and negative electrodes, once covered and/or filled with paste, are referred to as positive and negative plates, respectively. The role of the electrodes, themselves, is to transfer electric current to and from the battery terminals. Often, a primary limit to battery durability is corrosion of the electrode (e.g., current collector) of the positive plate.
Several methods have been proposed for inhibiting the corrosion process in lead acid batteries, and some of these methods have involved using carbon in various forms to slow the corrosion process. For example, Great Britain Patent No. 18,590 discloses a method designed to increase the life of a lead acid battery by protecting lead-based grids that form the positive electrodes of the battery from corrosion. This method involves treating the grids with a mixture of rubber, antimony, and graphite. The mixture is applied to the grids by either dipping the grids into the mixture or by brushing the mixture onto the grids with a brush.
As with all coating methods of this type, however, the resulting coating is relatively thick. Often, these coatings do not adhere well to the surfaces of the electrodes, and they have a tendency to fracture and flake off of the electrodes. Furthermore, additives in the coating may reduce the conductivity of the electrodes and inhibit the electron exchange processes of the lead acid battery.